Chemistry, 15.11.2019 02:31, williejaroid123

Classify the possible combinations of signs for a reaction's δh and δs values by the resulting spontaneity

a. δh is positive and δs is negative

b. δh is positive and δs is positive

c. δh is negative and δs is positive

d. δh negative and δs is negative

for a, b, c and d find out which of following they are:

1. spontaneous as written at all temperatures

2. spontaneous in reverse at all temperatures

3. spontaneous as written above a certain temperature

4. spontaneous as written below a certain temperature

they can only have one answer but 2 can have the same answer

Answers: 2

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Answers

answered: steven0448

Answer :

(A) ΔH is positive and ΔS is negative → (2) Spontaneous in reverse at all temperatures

(B) ΔH is positive and ΔS is positive → (3) Spontaneous as written above a certain temperature

(D) ΔH negative and ΔS is negative → (4) Spontaneous as written below a certain temperature

Explanation :

According to Gibb's equation:

$\Delta G=\Delta H-T\Delta S$

$\Delta G$ = Gibbs free energy

$\Delta H$ = enthalpy change

$\Delta S$ = entropy change

T = temperature in Kelvin

As we know that:

$\Delta G$ = +ve, reaction is non spontaneous

$\Delta G$ = -ve, reaction is spontaneous

$\Delta G$ = 0, reaction is in equilibrium

(A) ΔH is positive and ΔS is negative.

$\Delta G=\Delta H-T\Delta S$

$\Delta G=(+ve)-T(-ve)$

$\Delta G=(+ve)$

The reaction is non-spontaneous at all temperatures or spontaneous in reverse at all temperatures.

(B) ΔH is positive and ΔS is positive.

$\Delta G=\Delta H-T\Delta S$

$\Delta G=(+ve)-T(+ve)$

$\Delta G=(+ve)$ (at low temperature) (non-spontaneous)

$\Delta G=(-ve)$ (at high temperature) (spontaneous)

The reaction is spontaneous as written above a certain temperature.

$\Delta G=\Delta H-T\Delta S$

$\Delta G=(-ve)-T(+ve)$

$\Delta G=(-ve)$

The reaction is spontaneous as written at all temperatures

(D) ΔH is negative and ΔS is negative.

$\Delta G=\Delta H-T\Delta S$

$\Delta G=(-ve)-T(-ve)$

$\Delta G=(+ve)$ (at high temperature) (non-spontaneous)

$\Delta G=(-ve)$ (at low temperature) (spontaneous)

The reaction is spontaneous as written below a certain temperature.

answered: Guest

mechanics (greek is that area of science concerned with the behaviour of physical bodies when subjected to forces or displacements, and the subsequent effects of the bodies on their environment. the scientific discipline has its origins in ancient greece with the writings of aristotle and archimedes[1][2][3] (see history of classical mechanics and timeline of classical mechanics). during the early modern period, scientists such as galileo, kepler, and newton laid the foundation for what is now known as classical mechanics. it is a branch of classical physics that deals with particles that are either at rest or are moving with velocities significantly less than the speed of light. it can also be defined as a branch of science which deals with the motion of and forces on objects. the field is yet less widely understood in terms of quantum theory.

explanation:

answered: Guest

there are no statements provided but here is why:

sulfur belongs to group 16 because it can be found in nature whether it is in a free or combined state.

hope this